Taking Your GIS to the Field

by Michele Mattix
January, 2016

GIS from Office to Field

Geographic Information Systems, or GIS, is work that is done primarily on a computer in an office. It is used to map real-world features and geographic data. As such, many places of business use GIS to keep track of things in the field. Things such as power poles, road signs, hiking trails, parking lots, communication towers, buildings, fire hydrants… and the list goes on and on.

Quite often, it is not only convenient but essential to take your GIS out into the field. Maybe the shape of the parking lots has changed in the years since the data were first digitized. New power poles have been installed. Old fire hydrants replaced with newer one. Or perhaps you need to use the data, such as hiking trails, to locate the source of an emergency call. There are many reasons why a person or organization needs to take their GIS into the field.

How Can I Take My GIS into the Field

The big question isn’t why, but how. How can I take my GIS into the field to do what I need it to do?

Nowadays it is most convenient to use a smart phone or tablet to accomplish this mission. If you have a Windows tablet capable of running ArcMap, you can simply take ArcMap out in the field, connect your Windows tablet to an internal or external GPS receiver, and work with your GIS as if you were in the office. I’ve done this. It’s not much fun. ArcMap was not made to be used in the field.

Barring this, you will need some field software or application capable of working with your GIS data and a device to run it on. There are many such applications and your options depend on your mobile device. Dividing the world of options into two categories depending on the actual mobile device, we’ll begin by looking at some of the options available to run on smart phones and tablets.

1. Smart Phone & Tablet Solutions

We love our smart devices. That’s what makes these solutions so likeable – you can use them on a device you probably already have and know how to operate. Smart devices have cameras and many of the GIS apps allow you to take photos of your field assets and store them with the feature.

Here are the pros and cons of using GIS apps on smart devices:

Pros:

No dedicated GPS unit necessary – you can use a device you probably already have with you most of the time.

Lower cost hardware (compared to Windows Mobile solutions, below) – if you damage a smart phone or tablet, you can replace it easily for a fraction of the cost of a dedicated GPS device.

Easy to use applications – use your fingers to interact with fairly intuitive apps.

Work in connected and disconnected modes – when connected to the internet via Wi-Fi or cellular modem, you can synchronize your field edits with a database, stream basemaps, and receive updates from the office. When not connected, you can save your project on your device and then synchronize when within range.

Cons:

Poor accuracy due to the engineering specifications of the GPS chip in the smart phone/tablet. Devices with a cellular modem can supplement the GPS position via cell tower triangulation, but this may not be available when working in remote locations nor accurate enough for your needs. (Note: There are several brands of external GPS receivers that can connect to your smart device to improve the accuracy somewhat.)

Poor battery longevity. Using the GPS functionality really drains the battery quickly. You will need supplemental power to either recharge or extend your smart device’s battery.

Subscription-based services. Most of the smart device GIS workflows rely on cloud services to which you must subscribe. The recurring cost to subscribe usually brings these solutions in the same price ballpark as the older dedicated device solutions (see below).

Now let’s take a look at a couple popular apps for GIS data collection on smart devices. (Another area you may want to look into is developing your own GIS apps to run on smart devices. Esri offers the tools to do this within their ArcGIS platform and there are non-Esri options available, too.)

a. Esri Collector

This is a free app that runs on supported iOS and Android devices. The app works in conjunction with Esri’s ArcGIS Online cloud services. To access the functionality required to use the Collector app, you need to have an ArcGIS Online organizational account. The free accounts will not work with Collector.

With Collector, you build your geodatabase and map in ArcMap, publish a map service, then use the service to build a web map in ArcGIS Online. You then configure the web map to work with Collector and then access the map through the Collector app. Any data you collect with Collector will be synchronized with the web map in ArcGIS Online. Depending on your workflow, the data can also be synchronized directly with your enterprise geodatabase, or you may need to manually download the field edits and integrate them with your office file geodatabase.

For organizations who have an Esri Enterprise License Agreement (ELA), the appropriate licenses are usually included in the license agreement thus making this solution easy and affordable. For smaller GIS shops who have neither an ELA nor an organizational account of ArcGIS Online, this solution may be cost prohibitive. However, the cost of a smart phone or tablet is much more affordable than that of a dedicated GPS device (see below) and the cost of an ArcGIS Online subscription may be cheaper than dedicated Windows Mobile GPS field software. It all depends on what’s being compared.

Another issue with the Collector workflow is that you cannot get high accuracy GPS data using a smart phone or tablet. External GPS receivers can be purchased and connected to your smart phone/tablet to help boost the accuracy, but these are usually limited to within a meter. If you need higher accuracy, then this is not a good solution at this time. Technology changes quickly and we may soon see the ability to collect high accuracy GPS data with the Collector app.

b. Trimble TerraFlex

Trimble has been a big name in the field data collection world for many years. Their line of Windows Mobile GPS solutions have been the standard for high accuracy field work. TerraFlex is Trimble’s cloud-based field software that can run on iOS and Android devices as well as Trimble Windows Mobile GPS devices such as Junos and GeoExplorers.

TerraFlex includes a field application that runs on the mobile device which works in conjunction with a web application. You can import your GIS data into a project which you set up via the web application. The project is then shared with TerraFlex which you use to update existing data and collect new data. The updates are shared via the cloud and are accessible via the web application for exporting back into your GIS.

TerraFlex is available as a subscription service.

Tips for Choosing a Smart Device GIS App

These are just a few of the GIS-ready GPS solutions for smart phones and tablets. There are many others, each with its own bells, whistles, and caveats. Be sure you understand the costs of a solution before you sign up. A few questions to ask before choosing a solutions:

Does the solution require special equipment?

Is there a recurring subscription fee?

Does it work directly with GIS data formats or must you convert from one format to another?

2. Dedicated GPS Device Solutions

A dedicated GPS device is one which you buy expressly for collecting GPS data, unlike a smart phone/tablet which often serves various functions. Before GPS apps on smart phones and tablets, these dedicated GPS devices were the only way to go. The vast majority of these units – at least from a GIS user’s perspective – are ruggedized devices which use the Windows Mobile operating system. Nearly all of these devices have built-in cameras which can be used to attach photos of your field assets to the attributes of the feature.

Windows Mobile GPS devices are like mini-PCs for the field and you must purchase the GPS field software you want to use on the device separately. The most popular of these applications being Esri’s ArcPad and Trimble’s TerraSync. Hardware manufacturers include Trimble, Leica, and Juniper. Some software, like Esri’s ArcPad, can run on any Windows Mobile device regardless of the manufacturer. Others, like TerraSync which is a Trimble software product, only run on Trimble hardware.

Pros:

These solutions have been around for a long time which means it is easy to find training, help, and support for them.

High accuracy – the accuracy of a GPS solution is primarily a function of the GPS chip in the device. Smart phones and tablets have very basic GPS chips. These Window Mobile GPS devices have beefier GPS chips. Because you pay for higher accuracy, you typically begin the buying process by identifying your accuracy requirements and then choosing from among the models that meet your needs. If you need high accuracy (consistently at sub-meter and even down to centimeter level), then these are still the best solutions.

Ruggedized – most of these devices are ruggedized for fieldwork. You can drop them on concrete, in mud, in water, and they’ll keep on going.

Long-lived batteries – like I said, these devices are made for fieldwork. A charged battery will easily see you through a full day of field work.

Cons:

Expense – these solutions cost from $600 on up to several thousand dollars and that’s just for the hardware. The software costs an additional $600 – $2,000.

Clunky workflows – the field software for these devices definitely comes from a time before smart phone apps. The interfaces are unintuitive and the workflows are fraught with pitfalls.

Slow to update – ArcMap is updated with cool new functionality but it takes months before these field solutions are compatible with the latest version.

Here I will discuss ArcPad and TerraSync, though there are other solutions.

a. ArcPad

ArcPad is one of Esri’s mobile solutions for Windows Mobile devices (ArcPad also runs on Windows devices). It is like a mini-ArcMap which allows you to take your GIS data out into the field and have it look and behave very similarly to how it does in the office.

ArcPad works in conjunction with ArcMap, though you can use it separately. You prepare your data and map in ArcMap and then use a special ArcPad toolbar to create an ArcPad project. The ArcPad project is then passed over to the mobile device where you can open it up in ArcPad, turn on the GPS, and start editing your data. Back in the office you transfer the data back to your PC and use the same ArcPad toolbar to integrate the field edits with your GIS.

If you want high accuracy and you are using ArcPad on a Trimble device, you can purchase Trimble Positions, an extension product that allows various options for differentially correcting your GPS data to the highest accuracy your hardware is capable of.

b. TerraSync

TerraSync is Trimble’s mobile software for Trimble Windows Mobile GPS devices (Juno, GeoXH, GeoXT, etc.). It runs on the mobile device and works in conjunction with Trimble’s GPS Pathfinder Office software. You can import your GIS data into Pathfinder Office, create custom projects (data dictionaries), and transfer the GPS project template to your mobile device. You use TerraSync to generate a new project based on the template and to collect new GPS data and update existing data.

When finished in the field, you transfer the data back to the PC for post-processing in Pathfinder Office and then export the data back to your GIS. Depending on your workflow, you may need to manually edit the GPS data to integrate it with your existing GIS data in ArcMap.

Recreational GPS Solutions

Recreational GPS units include those made by Garmin, DeLorme, and others. They are called recreational because they were designed to be used by hikers, fishermen, and outdoorsy types who would rather use a GPS unit than a paper map. They are not designed for the GIS professional and they do not have workflows specific to GIS.

Because of this, you usually have to do a fair amount of tinkering to make these solutions work for GIS.

Pros:

Prices – these units are about as cheap as you can get costing less than $100 up to a about $500.

Simple – these devices are uncomplicated.

Rugged and small.

Cons:

Proprietary operating system / software – they come with their own GPS software which is usually a bit awkward to figure out.

NOT designed for GIS – you may or may not be able to load existing data onto the device and if you can, it will require converting from one format to another using third-party tools. Ditto for getting the data off the device and into your GIS.

Accuracy – it’s usually in the 2-5 meter range.

Hybrids

There is at least one hybrid device — Leica’s ZenoCollector. It’s a ruggedized, dedicated high accuracy GPS device that comes with the Esri Collector app. No doubt there are other hybrids between the old dedicated units and the newer smart device apps.

So Many GPS Options – Choose Wisely

The state of mobile GIS has been in flux for a few years as the dedicated Windows Mobile GPS devices give ground to smart phone/tablet solutions in most areas except high accuracy. If you are new to mobile GIS, the terrain can seem impossible to navigate. I hope this article provides some guidance for you when selecting your mobile GIS solution.

Are you an experienced mobile GIS user? What solution do you use and why?